Glow lamp



Dec. 19, 1933. s F MARvlN ET AL 1,940,630

GLOW LAMP Filed May 8, 1931 Patented Dec. 19, 1933 UITED STTES PATENT OFFICE Kayatt, New York, N.

Y., assignors to Radio Inventions, Inc., New York, N. Y., a corporation of New York Application May 8, 1931. Serial No. 535,932

3 Claims.

The present invention relates to gaseous glow lamps for television apparatus and the like.

More specifically this invention relates to gaseous glow lamps wherein the useful optical output is obtained in a concentrated beam or at a point of restricted area.

This invention relates particularly to the construction, form, size and mode of operation of such gaseous glow lamps used as a light source variable in accordance with changes of the electric exciting current applied thereto.

One object of this invention is the projection of a concentrated beam of light capable of rapid fluctuation in intensity and of being directed, focused or otherwise acted upon by optical means.

Another object is to produce such a beam in a tube of small physical dimensions and remote from the electrodes thereof.

Another object is the provision of a small, rugged and compact television lamp suitable for commercial production and use.

A further object is to provide a signal re-. sponsive glow lamp for television work and the like, in the form of a unitary structure readily interchangeable or replaceable with other similar unitary structures.

Otherobjects and uses of our invention will be apparent from the accompanying drawing, where:

Fig. 1 illustrates in cross section, one form of our invention.

Fig. 2 illustrates an alternative detail of Fig. 1.

Fig. 3 illustrates an alternative electrode form. In Fig. 1, the numeral 1 represents a suitable vessel of transparent or translucent material in the form of an inverted U. The link 2 which connects the two legs of this U is in the form of a tube of cross section narrowed with respect to the cross section of the parallel legs of the U.

Electrodes 3, preferably not larger in diameter than the cross link, are supported in each parallel leg by suitable mechanical means so as to be'near the ends of the cross link. The narrowed cross link 2 is covered by an opaque coating 4 upon the portions thereof wherefrom the escape of light is not desired. This link may be still further narrowed at the point where it is not coated, in order to secure greater concentration of the light source, as shown in Fig. 2. The electrodes are supported by wires 5 enclosed in at protecting coating 6 which may be of any suitable insulating material, such as quartz, isolantite, or the like. At '7 is indicated a seal between the wires 5, the insulating coating 6, and the outer envelope of the vessel 1. 8 indicates the sealed-off tubulature used for the purpose of exhausting and filling the vessel 1 with the desired gas, which may be one of the 6 monatomic inert gases, such as neon or the like.

9 represents a base which may be of any suitable material, preferably insulating, and V in which are fastened the two parallel legs of the vessel 1 by any suitable means such as cement 9. This base carries prongs 10 which are connected to electrode leads 5 by means of conductors 11 and serve to make contact with the prongs of a socket into which the entire structure can be inserted as a unit.

12 indicates the portion of the cross leg which is not covered by any opague material, from which point the useful optical output of our invention proceeds.

In Fig. 3 is shown partly in cross section, another form of electrode where the insulation 6 projects beyond the electrode proper 3' which in this form fits snugly the opening in the insulator, and may be hollow if desired. Such an arrangement may demand lower voltages than a solid electrode.

The gas which fills the interior structure is at such suitable pressure that it will glow with great intensity in the cross tube 2, and the voltages applied to the electrodes are of such an order of magnitude as to suitably cooperate with respect to the nature and pressure of the gas content of the structure.

By suitably choosing the gas pressure and the voltage with relationship to one another and to the dimensions of the various portions of the vessel, we have discovered that it is possible to cause the major portion of the luminous discharge to be concentrated within the constricted portion 2 thereof. Furthermore the opaque coating 4 prevents any undesired emission of light except at the window 12.

We prefer to fill our tubes with gas while operating voltages are applied, in order to secure optimum pressures thereof.

The electrodes 3 of our invention may be of any suitable shape, form or material, and any spattering from the electrodes will not interfere with the proper operation of the tube since-the window 12 is remote from these electrodes. We 105 prefer to employ electrodes coated with or composed of materials or compounds of high electron emissivity, such as alkali metals, alkaline earth oxides, magnesium or the like. We can also use hollow cup-like electrodes having the insulating sleeve projecting beyond the edge thereof, as indicated in Fig. 3.

By placing our electrodes at a considerable distance from the, seals of the vessel, we prevent unwanted action of the discharge proper upon the seals. Furthermore the protective coating 6 prevents a discharge from occurring along the length of the wire supporting these electrodes.

By making the parallel chambers of our tube of considerable size, we are able to employ a large quantity of gas, with consequent prolongation of the effective life of the tube. These chambers may also be optically screened, if the light produced therein is objectionable.

One advantage of our structure in comparison with ordinary forms of neon glow lamps is that we can confine our useful luminous output to a narrow beam, which may be readily applied at a desired point.

It is possible to omit the opaque coating 4 it a wider beam is desired.

- Another important advantage of our construction is that the tube producing the maximum light and at the same time heat, is so exposed to the air as to be easily cooled thereby.

Furthermore the physical structure producing this beam is of such shape and size as to allow it to occupy the approximate focal point of a lens or mirror structure, which is not true of the large luminous areas previously employed.

Another advantage of our invention is that one unit can be quickly and easily replaced by another in case of failure, and it will not be found necessary to readjust any optical devices used in connection therewith, since the source of light will be at exactly the same position in all units constructed after our invention and of a standard size and form.

While a considerably wider range of gas pressure and voltage may be used, we have found 6 to 12 mm. of mercury and 200 to 500 volts very satisfactory. Results quite satisfactory in many respects are possible with pressure from 2 to 20 mm. as well. With pressures too low, a weak diffused glow occurs, and with toohigh pressures a thread-like discharge predominates.

While we have shown and described a specific form of our invention and mentioned specific materials for the parts thereof, we do not desire to limit ourselves to such exact materials or exact forms, except insofar as they are specifically set forth in the claims hereunto appended.

We claim:

W1. A gaseous glow lamp comprising a U shaped vessel, with its cross member of small cross section compared with its other legs, having cold electrodes sealed in its legs with their active discharge portions substantially opposite the point of junction of said legs and said cross member and an opaque coating over part of its cross member, said vessel being filled with gas at such pressure that the luminousdischarge is substantially confined to the cross member thereof.

2. A television glow lamp, including two parallel chambers, a partially optically screened constricted connecting chamber, an electrode in each parallel chamber, substantially centrally located therein, relative to the bore thereof, and substantially opposite the centre of the beginning of the constriction of the connecting chamber where it joins each parallel chamber, a base holding the unconnected ends of the parallel chambers, and projecting connecting pins in said base and connected to said electrodes.

3. A device for transforming rapidly fluctuating electrical energy into similar fluctuations of luminous energy, including a tube having a plurality of gas storing electrode chambers connected by a constricted light producing cross member, said gas storing chambers and said light producing cross member having internal communication with one another and having their exterior defining walls impervious to gas, a plurality of electrode structures one within each of said electrode chambers, having each a discharge surface exposed to any gaseous matter within said electrode chambers and located opposite the junction of the light-producing and the gas storing chambers, and an insulating portion substantially surrounding all parts of the electrode structure except said discharge surface, means for supporting saidelectrode structures from one end of the respective electrode chambers, means for the impervious sealing of said conductors within the walls of said electrode chambers and said electrode supporting means, opaque light confining means upon at least a portion of said light producing cross member, and a gas filling including a gas inminescent under electrical discharge therethrough.

STUART F. MARVIN. PH J. KAYATT. 

